screenshot 0.9.3

• 2026-08-20

• Bug fixes

  • screenshot() failed with 'C:/Program' not found when a path held a space, such as a package installed under C:/Program Files (#1). The command is now quoted with shQuote() for the shell of the platform. The quote argument of screenshot() did not help, because it wrapped the whole command in single quotes, which cmd.exe does not treat as quoting. It is deprecated and ignored now.
  • index2xy() returned a column shifted by one for an index on the last row of a matrix, which could make locate_image() report a wrong position.
  • hex2little_endian() padded an odd number of digits in the middle, so the file size in the BMP header of create_header() was wrong.
  • save_clipboard_image() raised an error instead of returning NULL when the clipboard held no image.
  • locate_image() applied round() and floor() to the wrong operand because of the precedence of the native pipe.
  • hay2needle() lost the defaults of w and h.
  • screenshot_exists() raised an error when bin_dir did not exist.

• Search speed

  • locate_ndl_in_hay() counts only the values of the needle image with match() and tabulate(), instead of building a frequency table of the whole haystack image with dplyr. The frequency table was where almost all of the time went.
  • One position of the rarest shared value is now used as an anchor, so the candidates follow directly from it and the repeated intersect() is no longer needed. A few pixels spread over the needle image reject a candidate before the whole block is compared.
  • On a haystack image of 1920 x 1280 the search went from about 42 seconds to about 0.25 seconds, and a needle image that is absent from the haystack image from about 110 seconds to about 0.3 seconds.

• New features

  • locate_image() and locate_ndl_in_hay() gain tol to allow a difference of a few grayscale levels. The default 0 keeps the exact match, which is right for a screenshot saved as PNG; a positive value helps for an image that has been through a lossy format such as JPEG.

• Other changes

  • display_size() falls back to PowerShell where wmic is not available.
  • crop_image() reports an area outside of the image.
  • display_corner() reports an unknown corner name.
  • tests/testthat.R now runs the tests, and unit tests were added.

screenshot 0.9.2

• 2025-08-27
  • reset_transparent() to reset transparent color.

screenshot 0.9.1

• 2024-05-30
  • display_corner() to locate image in the display corner.
  • save_clipboard_image() to save clipboard image as a png file.

screenshot 0.9.0

• 2023-08-11

• First release

  • screenshot() to take a screenshot.
  • locate_image() to locate a image position on a screenshot image.

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